Illumination system based on active and passive illumination devices

Abstract

Illumination systems are described for illuminating a target area, e.g., a floor of a room, using active illumination devices in optical communication with passive illumination devices. The active and passive illumination devices of the illumination system are configured and arranged relative to each other in a variety of ways so a variety of intensity distributions can be provided by the illumination system. Such illumination system is implemented to provide light for particular lighting applications, including office lighting, garage lighting, or cabinet lighting.

What is claimed is: 
     
       1. An illumination system, comprising:
 an active illumination device comprising
 one or more light emitting elements arranged to emit light in a forward angular range having a prevalent propagation direction along a first direction, and 
 first redirecting optics arranged to receive light from the one or more light emitting elements and to direct the received light in a backward angular range having a prevalent propagation direction along a second direction, the second direction having a first component antiparallel to the first direction and a second component orthogonal to the first direction; and 
 
 a passive illumination device comprising second redirecting optics, 
 wherein an entirety of the active illumination device and an entirety of the passive illumination device are spaced apart from each other by a first non-zero distance along the first component of the second direction and by a second non-zero distance along the second component of the second direction, and 
 wherein the second redirecting optics of the passive illumination device are configured to receive light output by the first redirecting optics of the active illumination device and direct the received light toward a target surface. 
 
     
     
       2. The illumination system of  claim 1 , wherein
 the active illumination device comprises a first support, 
 the passive illumination device comprises a second support, 
 the first support and the second support are configured to position the first redirecting optics of the active illumination device at a distance further from a mounting surface than the second redirecting optics of the passive illumination device. 
 
     
     
       3. The illumination system of  claim 2 , wherein the second support of the passive illumination device positions the second redirecting optics of the passive illumination device at the mounting surface. 
     
     
       4. The illumination system of  claim 2 , wherein the mounting surface is a ceiling. 
     
     
       5. The illumination system of  claim 4 , wherein
 the first direction is orthogonal to the ceiling, and 
 the second redirecting optics are configured to output light within +/−40° with respect to the first direction. 
 
     
     
       6. The illumination system of  claim 1 , wherein the first redirecting optics comprise an interface configured to transmit at least some of the light from the one or more light emitting elements, such that a propagation direction of the transmitted light is oriented towards the target surface. 
     
     
       7. The illumination system of  claim 6 , wherein the first redirecting optics and the second redirecting optics are configured such that light from the active illumination device and light from the passive illumination device overlap on the target surface. 
     
     
       8. The illumination system of  claim 1 , wherein the one or more light emitting elements are light emitting diodes. 
     
     
       9. The illumination system of  claim 1 , wherein the second redirecting optics of the passive illumination device comprises a curved reflector. 
     
     
       10. The illumination system of  claim 9 , wherein the curved reflector is a convex reflector. 
     
     
       11. The illumination system of  claim 1 , wherein the second redirecting optics of the passive illumination device comprises a Fresnel reflector. 
     
     
       12. The illumination system of  claim 1 , wherein each of the active illumination device and the passive illumination device is elongated in a direction orthogonal to the first and second directions. 
     
     
       13. The illumination system of  claim 1 , wherein the active illumination device comprises a light guide configured to guide light from the one or more light emitting elements to the first redirecting optics. 
     
     
       14. The illumination system of  claim 1 , wherein the active illumination system further comprises refractive optics configured to output some light from the one or more light emitting elements in and around the first direction.